Fluid heater furnace



Dec. i8, 1956 w. JUNKERMANN FLUID HEATER FURNACE 2 Sheets-Sheet l FiledMarch 31, 195s FIGB . INVENTOR /ofgcmg dm kefmazzzz ATTORNEY Dec. 18,1956 w. JUNKERMANN FLUID HEATER FURNACE 2 Sheets-Sheet 2 Filed March 5l,1953 FIG.2

INVENTOR azzgcfimiferma 7m ATTORNEY United States Patent() FLUlD HEATERFURNACE Wolfgang Junkermann,-Oberhausen, Rhineland, Germany, assignor toThe Babcock & Wilcox Company, New York, N. Y., a corporation of NewJersey Application March 31, 1953,'Seral No. 345,887

6 Claims. (Cl. 122-240) The present invention relates to a uid heaterfurnace having as its firing means a plurality of cyclone furnaces eachof which is generally of the type disclosed, for eX- ample, in U. S.patent Kerr et al. 2,594,312, April 29, 1952. In one form, the Vcyclonefurnaces may be arranged at a common elevation, in separate uprightouter walls of a fluid heater furnace having its internal space dividedby upright fluid cooled Awalls inwardly Aspaced from the discharge endsof the cyclone furnaces; the latter walls defining at their outer sidesseparate gas receiving chambers or wells into which the respectivecyclone furnaces discharge, and at their inner sides, a gas ow chamberor well through which the gases are directed into an upper radiationchamber, -of upwardly increasing ow area, in which a substantialproportion of the total uid heating surface is disposed.

Heretofore, in multiple cyclone furnace-fired units, the cyclonefurnaces are usually mounted in the front wall of a secondary furnace,lfor example, in a Vsingle horizontal row for a small number of cyclonefurnaces, whereas for accommodation of a larger number Yin a wall of thesame width, the cyclone furnaces are necessarily arranged in successiverows at separate elevations. However, with the latter arrangement, it isnecessary to provide a secondary chamber space of comparatively largevolume which ordinarily is not favorable to the maintenance of slagVfluidity within such a chamber.

The present inventive arrangement results .in the flame beingcontinuously directed over a slag dischargeopening provided in thebottom-of the secondary chamber, even when only one cyclone furnace isin operation for a partial load condition. This arrangement also enableseach cyclone furnace outlet to be brought 'close to a gas reflectingarch in the secondary furnace chamber without undue reduction in thesize of that chamber. In determining the size of secondary chamber to beprovided, there are two major .factors to be considered, namely, thetotal interior space must not exceed-a certain maximum value in orderthat the slag will remain liquid and, on the other hand, it must providea sufficient surface area so that with the hot combustion gasesimpinging thereon, and being deected thereby, the liquid slag particlescontained Vtherein will still become separated therefrom.

The foregoing relationshipsfhave .usually beenestimated on the basis oftotal heat input per hour per unit of furnace volume, suitably accordingto the formula Q/ V wherein Q denotes the traversing heat quantity in lkilogram calories per hour 106 kcal./hr.), and V, the volume of thesecondary furnace lspace in cubic meters (111.3). However, it isnecessary to regard the two components Q and V separately, so that withA denoting the wall area of the space in square meters (m.2),

@ 1os kan.

and

V t 111.3 1D. me BI'Sp-I Accordingly, certain optimal operating valueshave been determined as follows:

Q 1.65 (1o6 kan) A- (m.2)(hr.)

and

V Z- 0.135 m.

With the customary multiple arrangement of cyclone furnaces, al1discharging into a common chamber, the foregoing values can only berealized with difficulty. From the foregoing rule, therefore, it followsthat in order to obtain favorable relationships also at partial loads,Vthe secondary furnace chamber lmust be divided into separate gas inletcompartments corresponding -to the number of cyclone furnaces. i

The various features of novelty which characterize my invention arepointed out with particularity in the claims annexed to and forming apartof Vthis specification. For a better understanding of the invention,its operating advantages and specific objects attained by its use,reference should oe had to the accompanying drawings and descriptivematter in which l have illustrated and described a specific embodimentof my invention.

Of lthe drawings:

Fig. 1 is a vertical section of a iiuid heater furnace constructed as anembodiment of the invention;

Fig. 2 is a vertical section of Fig. l, taken along-line 2 2; and

Fig. 3 is a horizontal section of Fig. 2, taken along line 3-3.

The drawings show a liuid heater furnace arranged for use ina vaporgenerating unit, for example, as an integral component of the totalassembly. Included therefore is a vertically elongated 'furnace sectionA of substantially rectangular formation in a horizontal plane, andhaving as its firing means a plurality of cyclone furnaces 1, 2, 3`which are mounted in upright outer walls 4, 5, 6 toward the bottom,each of which walls is formed with a reentrant wall section having itslower v`portion 7 inclined downwardly and outwardly for assembly of acycione furnace therein, in right-angled relation thereto. Interiorly offurnace section A, at a common level with primary furnaces 1, 2, 3,upright walls or partitions 8, 9, it? serve to divide the furnacesection A into three secondary furnace compartments 11, 12, 13, intowhich the respective cyclone furnaces separately discharge; walls 8, '9being arranged parallel to one -another and perpendicular-to wall 5, andwall 1t? being arranged perpendicular vto walls 8 and 9, and parallel tothe upright rear furnace wall 14. The partitions 8,19,

10 thus dene an interior well or gas flow region 15/of rectangularcross-section which opens upwardly through progressively increasing owareas into .a `radiation chainber 16 extending throughout the remainingheightof the setting. All walls of the cyclone furnaces 1, 2, 3, of

the well 15, and of the radiation chamber 16, Vare iluid cooled andformed with fluid heating tubes of the associated vapor generator. Suchtubes, for example, are arranged and connected so as to be supplied withVliquid f from lower headers 17, 1S, 19, 2), 21, 22 Vand to dischargeinto theelevated boiler drum 23, either by direct connections, orthrough intermediate headers 24, 25, .26, 27, 28, andriser tubes 29,V30, 31, 32, 33, themajorityof which conductors and connections arediagrammatically indicated. The arrangement of the necessary -downcomersand their connections is omitted for simplitication of the graphicdisclosure.

In the wall areas of cyclone furnaces 1, 2, 3, of the secondary furnacespace 12, and of the well 15, to 'an Y elevation indicated by line R,above the cyclone furnaces,

the wall tubesV are provided on the tire side, in known manner, withmetallic studs, not shown, which studs are embedded within a coveringlayer of refractory material 34, and surrounded outwardly by a heatinsulating jacket 35 and arsheet metal casing 36.

A row `of tubes 37, starting at the lowermost uid distributing header17, extends` alongthe bottom 38 of theV Vsecondary chamber 12 auditsfrontV wall 39, and continues upwardly along the inclined inner end wallof cyclone furnaceZ, thence along the front wall .41 of radiationchamber 16. An additional tube row 42 extends from header 17 upwardlyand rearwardly along an iu-V Y I have illustrated and descn'bedvhereinVa specific formY well 15. It is not until the combustion gases enterthe Well that their temperatures fall below the melting ternperature ofthe slag whereupon, inpassing through the upper slag screen 53, thegases are further cooled to insure that the gases will have temperatureswhich lie f below the melting point Vofthe slag when the gases enterthe'radiation space 16.

The heating gases iiow upwardly through `the radiation space 16,` incontactgwith a tubular superheater componentas shown, and then throughsucceeding liues 69 and 70 in each of which flues other heating surfacemay be disposed, as herein indicated'only in part.

While in accordancewith the provisions ofthe statutes of the inventionnow known tome, those skilled in the art will understand that changesmay be made in the form of the apparatus disclosed without departingfrom the spirit of the invention covered by my claims, and

that certain features of the invention may sometimes bev used toadvantage without a corresponding use of other features. Y I

l. A furnace unit having a pair of upright outer Walls f formingopposing lateral boundaries of a furnace chamtinuation, along opposinglateral walls 49, 49 of the radiation chamber 16. y

Tubes 51in another group, having lower ends connected in rows to header17, extend upwardly through the inclined furnace floor portion 43,between rear wall tubes 42, to form an inclined tubular slag screen 52,and

Y then the front partition 10 between well A15 and the sec-V ondaryfurnace compartment 12. The tubes 51 are then inclined upwardly towardthe rear of the furnace toform a tubular slag Vscreen 53 disposed acrossthe lower, gas inlet end of radiation chamber 16. The tubes 51 are thencontinued upwardly in front of rear wally 46for suitable riserconnectionsY to upper drum 23. Other groups of tubes 54, 56 yalso extendupwardly from header 17 to form the two opposing walls 57, 5S of well15, whence they are continued upwardly along the opposing side wallportions 49, 49.

In the embodiment disclosed, each of the cyclone furnaces 1, 2 and 3respectively, is of cylindrical forma- .tion about a central axis whichis inclined downwardly toward a separate one of the outer wells orcompart- Yments 11, 12, 13. A fluent mixture of solid fuel particlesVtially arranged secondary air inlet 62 extending lengthwise of thecyclone chamber. Combustion of the fuel takes place at a rapid rate andat temperatures above the ash fusing temperature, whereby slag formed onthe inner wall surfaces continuously drains along inner Wall surfacesfor discharge in molten condition throughV a bottom outlet 63 from thelowermost part of the chamber. The hot gases of combustion dischargethrough a central gas outlet 64 which is suitably defined by a reentrantannular throat section of the inner end wall. In the bottom Wall 38,vertically below the partition 10, and adjacent partitions 8, 9 thereare provided two slag outlets 65, 65 through which slag is discharged tothe exterior of the setting for ultimateV disposal. The hot gasesflowing through the cyclone outlets 64 enter the respective secondarychamberY compartments 11,712, 13 where they are caused to impinge on theupright depending walls 8, 10, 9, by which the gases are deflecteddownwardly and thus caused to flow along the furnace' bottom 38 inpassing through slag screen 52 intov the ber, upright partitionsinwardly spaced from said" lateral boundaries and respectively deiiningtherewith'separate gas receiving compartments, said partitions definingan interior well space arranged to receive heating gases from saidcompartments, and through which space said gases are directed, saidfurnace chamber having a bottom wall common to said compartments andsaid well space, and furnaces in which the combustion of slag-formingsolid fuel particles is effected, said furnaces having koutlets throughwhich gases of combustion from separate Y furnaces are dischargedV intothe separate compartments Vagainst the respective partitions anddeected'down- Wardly thereby toward said bottom wall, saidrpartitionshaving lower ends upwardlyspaced from said bottom wall at 'elevationsllower than said furnace outlets and defining Vtherewith areas throughwhich said gasesA flow into a lower portion of said well space. Y

2. A furnace unit according to yclaim l and further comprising iiuidconducting tubes forming a slag screen inclined across said well spaceinthe path of the gases entering from each of said combustion furnaces.Y

3. A furnace unit according tofclaim 2 and further comprising headermeans from which uid is supplied to the lower ends of tubes forming saidslag screen, and other fluid conducting tubes extending from said headermeans and providing fluid cooling means for at least one of saidpartitions.

4. A furnace unit according to claim 1 wherein said furnaces arerespectively formed as cyclone furnaces `of substantially circularcross-section about axes of substantially horizontal arrangement, saidfurnaces respectively having said gas outlets axially arranged'andhaving slag outlets opening into said compartments at elevations belowysaid gasoutlets, andV a slag discharge outlet in said bottom chamberwall at a location vertically below one of said partitions. f Y

5. A furnace unit having opposing upright walls arranged in two sets andforming theV lateral boundaries of a furnace chamber of substantiallyrectangular'horizontal cross section, upright partitions inwardly spacedfrom three of said lateral boundaries and defining therewith an equalnumber of separate gas receiving compartments, one of said partitionsextending between the remaining two partitions and arranged in abuttingrelation thereto said partitions defining with the remaining lateralboundary of said chamber an inner well space, said chamber having abottom wall along which heating gases are directed from saidcompartments into said Well space, and cyclone furnaces mountedrespectively in said three lateral boundaries and each adapted to elfectthe combustion of slag forming sulid fuel particles, said furnaceshaving separate outlets through which combustion gases and slag areseparately discharged at different elevations into the respectivecompartments, said bottom wall being formed with a slag-discharge areahaving portions respectively arranged in the vicinity of the lower endsof said partitions.

6. A furnace unit as defined in claim 5 and further comprising tubesextending in slag screen formation across the lower end of said well andcontinuing upwardly within the structure of one of said partitions,other tubes incorporated in the structures of the remaining partitions,and header means from which uid is supplied to al1 of said tubes, saidheader means being arranged exteriorly of said furnace unit at anelevation lower than said bottom wall.

References Cited in the le of this patent UNITED STATES PATENTS

